How is electric field at a point related to potential gradient?

What is potential gradient?

The electric field at the point is

Prove that electric field at a point is equal to the negative gradient of electrostatic at that point E=-dv/dr

Show that the electric field intensity at a point in an electric field is equal to the negative of the potential gradient of the field at that point. E = -(dV)/(dr)

Define intensity of electric field at a point at what points is the electric dipole field intensity parallel to the line joining the charges?

The SI unit of potential gradient is: